The ship had approximately 32 sublight engines, which were improved upon from the sublight engine system aboard the two Death Stars.[1] It also possessed at least six fusion reactor complexes at the Starboard, which allowed for redundancy and increased damaged resistance.[1]

The Supremacy was large enough to dock eight Resurgent-class Star Destroyers, six externally and two internally. It also crewed over 2,225,000 personnel, including officers, stormtroopers, gunners, vehicle engineers, factory workers, technical specialists, and communications staff.[1] It likewise possessed at least 10 military staging areas, each of which can accommodate a full corps of more than 36,000 stormtroopers.[1] The operations decks had floors of workstations filled with highly efficient operators. The vast majority of the crew were Sub-Adults (ie, too young for active combat deployment), and fully indoctrinated into the First Order myth of a chaotic galaxy requiring a strong, unflinching order to control it.[5]

Largely because of its role as the First Order's headquarters, not only was it able to carry stormtroopers into battle, but it was also capable of fixing, harboring, and building various ships in the First Order Navy in its onboard hangar bays,[2] two of which were large enough to even house and repair Resurgent-class Star Destroyers.[1] Aside from these, it also carried production lines, shipyards, army training grounds and even R&D labs.[7] The Supremacy also acted as one of the premier research labs and factories in the First Order, possessing industrial capabilities that rival that of even the most productive worlds under control of the regime, with its armored decks housing departments reserved specifically for the conception, research, and approval of new weapons and technology. It also housed well-stocked raw materials reserves, eight durasteel foundries, an asteroid mining complex for harvesting raw materials directly from asteroids fields, as well as state-of-the-art production lines. Training centers were present to indoctrinate young cadets into the military. As it carried all the supply lines, it also cannot be cut off from supply lines. Its capabilities were such that its destructive power was comparable to that of a full fleet, its production capabilities comparable to that of a planet, and acting as a testbed for the various military advances of the First Order.[1] It also possessed a detention center near the stern, as well as a commons area, an assembly hall that can fit 200,000 personnel, as well as at least 346 laundry rooms. The majority of the crew quarters were placed within the various central "city" blocks of the ship.[1]

It also possessed at least eight droid manufacturing facilities, one of which, P-3, achieved the top rank, as well as a ground vehicle manufacturing zone. In addition, the tips of the wings were reserved for top secret labs and dangerous weapons tests, and also possessed communications hubs. The starboard wing possessed a crew transportation causeway with an integrated tram system.[1]

Its main command bridge sat upon a massive structure sitting at the center of the ship, which had a similar design to that of the Mandator IV-class Siege Dreadnought, and to a lesser extent the Resurgent-class Star Destroyer. The bridge had access to displays that allowed for 360 degree views, thus allowing for lookouts over everything within the city-scape-like structures on the main "wing" of the destroyer.[2]

The Supremacy was able to track its targets through hyperspace using a combination of technological advances and brute-force data crunching. The Shipboard Tracking Control Complex boasted the data-shifting power of a planetary intel hub, linking its huge computer arrays to data banks loaded with centuries of combat reports and astrogation data. A static hyperspace field generated around the machines accelerated their processing power to unheard-of levels. A target's last known trajectory yielded trillions of potential destinations, but the system could assess them with terrifying speed.[1] This capability of tracking ships via hyperspace routes had its roots from the Tarkin Initiative.[5] The ship, owing to it being the central command ship, forwarding base, and the proverbial brain of the First Order's entire forces, was also entirely self-sufficient, to the extent that it did not need to worry about supply shortages. In addition, the vessel possessed thousands of heavy turbolasers, anti-ship missile batteries, heavy ion cannons, and tractor beam projectors.[1] The bow of the ship possessed ten heavy turbolaser towers. Its power was such that only the Death Stars and Starkiller Base rivaled it.[1] Its communication complex monitored the holonet traffic throughout the galaxy to identify trends and weaknesses that the First Order could exploit. As such, they also dispatched orders to various agents operating within both New Republic and independent space.[5]

The ship was built by the First Order at staggering cost within a secret birthplace within the Unknown Regions to act as the official capital of the First Order at the order of Snoke. Although various officers as well as allies of the First Order argued for a planet to act as their capital, Snoke insisted on using the Supremacy as the main capital of the group, refusing to designate it to a world either under direct First Order control or in the Unknown Regions, at least not until they succeeded in their goal of bringing the entire galaxy under their control and restoring the old Galactic Empire, as he aimed to restore the territory formerly belonging to the Galactic Empire and build upon it.[1] Armitage Hux agreed with the strategy to keep the capital of the First Order aboard the Supremacy, viewing it as a way to avoid the risk of it being destroyed in battle when mobile.[6]

Upon being completed, the Supremacy was kept hidden in the galaxy's Unknown Regions to keep it from being discovered. During the cold war, Snoke preferred to issue commands from this vessel to his minions.[2] In order to ensure it was not discovered, Snoke also had it hidden among the brightest stars within the Unknown Regions.[5] However, the Resistance nonetheless suspected the existence of the ship, nicknamed "Snoke's Boudoir" and tried to investigate the veracity of its rumored existence among the underworld, although even the more cynical members of the Resistance could not imagine just how gargantuan the ship was.[1] Prior to his defection to the Resistance, FN-2187 spent some time aboard the Supremacy whenever his stationed vessel, the Resurgent-class Star DestroyerFinalizer, was docked with the Supremacy, doing patrol routes and basic duties.[5] To his regret, he was unable to inform the Resistance of its existence prior to their encounter with it, as time simply did not permit it.[6] After the Hosnian Cataclysm, however, Snoke, determining that the time was right to unveil himself, proceeded to unveil the ship to the unsuspecting galaxy to pursue the Resistance.[1]

The Supremacy cut in two due to Vice Admiral Amilyn Holdo's sacrifice.

The Supremacy participated in pursuit of the fleeing Resistance fleet. Under the command of General Armitage Hux, the Supremacy followed the fleet, knowing they could not jump to hyperspace, as the Supremacy could trace them with new technology and that if the Resistance continued to run, they would eventually run out of fuel. Utilizing single heavy turbo laser batteries near the forward hangars, the Supremacy bombarded the Resistance as they ran, destroying a cargo ship immediately, a medical frigate and a corvette when they ran out of fuel.

Eventually, the Resistance evacuated their flagship, Raddus in transports. Hux then ordered the transports targeted instead of the flagship. While many transports were destroyed, in Hux's haste to stop the Resistance from fleeing to Crait he neglected to realize that Vice AdmiralAmilyn Holdo was preparing a jump to hyperspace while aimed directly at the Supremacy. Realizing too late what was about to happen, Hux could only watch as the Raddus sliced right through the right wing, destroying several escorting Resurgent-class Star Destroyers in the process as well. However, a large portion of the First Order's leadership was able to escape due to preparations set about by Snoke.[5] In addition, the ship itself, while significantly damaged from the attack, nonetheless remained functional, even though it was thought that the flagship was doomed.[6]

The ship was first unveiled via the BB-9E App-Enabled Droid toy by Sphero by going through various areas and collecting data. The initial data erroneously claimed that the length of the Supremacy was over 60km,[2] although the confusion was rectified by Pablo Hidalgo on his Twitter feed where he clarified that the measurement was actually referring to the ship's width via its wingspan.[3]